The HbA1c and all-cause mortality relationship in patients with type 2 diabetes is J-shaped: a meta-analysis of observational studies

Researchers combined results from observational studies of adults with type 2 diabetes. They compared HbA1c, a blood test showing average blood sugar over about three months, with deaths from any cause. The relationship was J-shaped: death rates were generally lowest around HbA1c levels of about 6.5% to 7.5%, and higher at both very low and very high levels. This shows an association, not proof that a particular HbA1c level causes or prevents death.

What this means for you: This does not support buying supplements or trying to push blood sugar as low as possible. HbA1c goals should be chosen with a clinician because other health problems, age, medicines, and low-blood-sugar risks matter.